mm/hwpoison: introduce per-memory_block hwpoison counter

Currently PageHWPoison flag does not behave well when experiencing memory
hotremove/hotplug.  Any data field in struct page is unreliable when the
associated memory is offlined, and the current mechanism can't tell
whether a memory block is onlined because a new memory devices is
installed or because previous failed offline operations are undone. 
Especially if there's a hwpoisoned memory, it's unclear what the best
option is.

So introduce a new mechanism to make struct memory_block remember that a
memory block has hwpoisoned memory inside it.  And make any online event
fail if the onlining memory block contains hwpoison.  struct memory_block
is freed and reallocated over ACPI-based hotremove/hotplug, but not over
sysfs-based hotremove/hotplug.  So the new counter can distinguish these
cases.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Naoya Horiguchi <[email protected]>
Reported-by: kernel test robot <[email protected]>
Reviewed-by: Miaohe Lin <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Jane Chu <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Yang Shi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions